More than 1,300 people were arrested in France during a fourth night of rioting before the funeral on Saturday of Nahel M, whose shooting by police sparked the unrest, in the Paris suburb where the teenager died.

The government deployed 45,000 police and several armoured vehicles overnight to tackle the worst crisis of President Emmanuel Macron's leadership since the "Yellow Vest" protests which brought much of France to a standstill in late 2018.

Macron postponed a state visit to Germany that was due to begin on Sunday due to the unrest, both countries said.

The interior ministry said on Twitter that 1,311 people had been arrested overnight, compared with 875 the previous night, although the violence was "lower in intensity".

Nahel, a 17-year-old of Algerian and Moroccan descent, was shot by a police officer during a traffic stop on Tuesday in the Paris suburb of Nanterre, where buses were halted and the area quiet on a damp Saturday morning after more overnight rioting.

Several hundred people lined up to enter Nanterre's grand mosque, which was guarded by volunteers in yellow vests, while a few dozen bystanders watched from across the street.

Some of the mourners, their arms crossed, said "God is Greatest" in Arabic, as they spanned the boulevard in prayer.

Salsabil, a young woman of Arab descent, told Reuters that she had come to express support for Nahel's family.

"I think it's important we all stand together," she said.

Marie, 60, said she had lived in Nanterre for 50 years and there had always been problems with the police.

"This absolutely needs to stop. The government is completely disconnected from our reality," she said.

The shooting of the teenager, caught on video, has reignited longstanding complaints by poor and racially mixed urban communities of police violence and racism. Macron had denied there is systemic racism in French law enforcement agencies.

"If you have the wrong skin colour, the police are much more dangerous to you," said a young man, who declined to be named, adding that he was a friend of Nahel's.

Shops ransacked

Looters have ransacked dozens of shops and torched 2,000 vehicles since the start of the riots, which have spread to cities such as Marseille, Lyon, Toulouse, Strasbourg and Lille.

More than 200 police officers have been injured, Interior Minister Gerald Darmanin said, adding that the average age of those arrested was 17.

Friday night's arrests included 80 people in Marseille, home to many people of North African descent.

Social media images showed an explosion rocking the old port area of the southern city, but no casualties were reported.

Rioters in France's second-largest city had looted a gun store and stole hunting rifles, but no ammunition, police said.

Mayor Benoit Payan called on the government to send extra troops to tackle "pillaging and violence" in Marseille, where three police officers were slightly wounded on Saturday.

In Lyon, France's third-largest city, police deployed armoured personnel carriers and a helicopter, while in Paris, they cleared protesters from the Place de la Concorde. Lyon Mayor Gregory Doucet has also called for reinforcements.

Darmanin had asked local authorities to halt buses and trams, while Macron urged parents to keep children at home.

The unrest has revived memories of nationwide riots in 2005 that forced then President Jacques Chirac to declare a state of emergency, after the death of two young men electrocuted in a power substation as they hid from police.

"Quite simply, we're not ruling out any hypothesis and we'll see after tonight what the President of the Republic chooses," Darmanin said on Friday when asked whether the government could declare a state of emergency.

Players from the national soccer team issued a rare statement calling for calm. "Violence must stop to leave way for mourning, dialogue and reconstruction," they said on star Kylian Mbappe's Instagram account.

Events including two concerts at the Stade de France on the outskirts of Paris were cancelled, while Tour de France organisers said they were ready to adapt to any situation when the cycle race enters the country on Monday from Spain.

Crisis meeting

Macron had left an EU summit in Brussels on Friday early to attend a second cabinet crisis meeting in two days and asked social media to remove "the most sensitive" footage of rioting and to disclose identities of users fomenting violence.

Videos on social media showed urban landscapes ablaze. A tram was set alight in the eastern city of Lyon and 12 buses gutted in a depot in Aubervilliers, northern Paris.

Darmanin met representatives from Meta, Twitter, Snapchat and TikTok. Snapchat said it had zero tolerance for content that promoted violence.

The policeman whom prosecutors say acknowledged firing a lethal shot at Nahel is in preventive custody under formal investigation for voluntary homicide, equivalent to being charged under Anglo-Saxon jurisdictions.

His lawyer, Laurent-Franck Lienard, said his client had aimed at the driver's leg but was bumped when the car took off, causing him to shoot towards his chest. "Obviously (the officer) didn't want to kill the driver," Lienard said on BFM TV.